I stumbled onto this while browsing the warehouse this morning. They appear to have several available. As with all warehouse deals, it is hard to tell exact quantity.
It seemed like a good price for the battery alone, as the kit brand new has never dipped below $120 (according to CCC at least).
I have never heard of the 3.0Ah battery, but I would assume it is compatible with the rest of the 40v line. The condition is used acceptable, but I have purchased greenworks batteries from the warehouse before and have not had any issues.
I would suspect the damage, if any, would be to the trimmer itself and not the battery.
Anyway, I thought I would share in case anyone could use this! Enjoy!
EDIT: for those that care, the battery appears to have a usb port , which might be useful in power outages or something similar.